Osteophony or Bone conduction is a way of transmission of the sound. It's just sound. In the aerial conduction, the sound waves pass through the outer and middel ear (amplification of the sound) to the inner ear, that transmits the information to the brain.
In the bone conduction, the sound doesn't pass trough the air. The sound wave is created by a transducer (a vibrator) and goes to the inner ear, passing through bones and soft tissues.